Joined by Nelly's mother - older sister Billie - and their mother, Sam took a sweet snap of Nelly dozing in her pram, while surrounded by Selfridges bags.
"My little nelly's 1st time shopping at Selfridges, she has been such a good little lady. 😚#niece #familyday #shopping #fashion", Sam captioned the picture.
Nelly, Billie's first child with fiancé Greg Shepherd, was born in July. She made her first TV appearance only a few weeks later on The Only Way Is Essex, where mum Billie revealed her name.
Billie also showed her fans on Instagram a picture from their busy shopping trip, captioning it: "Nelly very much enjoyed her first shopping trip to #selfridges with mummy, nanny and auntie ... 🙊👯😘👶💗"
Sam took an active role throughout her sister's pregnancy, and was even one of her birthing partners.
Just days after welcoming her daughter, TOWIE star Billie thanked her via Twitter.
"Laying here thinking how fantastic my sister @SamanthaFaiers was as one of my birthing partners I couldn't have done it without u x", wrote the new mum.